Six weeks after 67 people perished in a D.C. midair collision, the NTSB’s preliminary report exposes a history of near misses between commercial jets and helicopters at the airport.

The National Transportation Safety Board (NTSB) is calling for immediate action following a mid-air collision in January between an Army Black Hawk helicopter and American Airlines Flight 5342, which resulted in the deaths of 67 people.

The NTSB’s preliminary report on the Jan. 29 crash that killed 67 people said current helicopter routes allowed around the airport are an ‘intolerable risk to aviation safety.’